Graft copolymers of certain monomeric sulfonic acid compounds on certain nu-vinyl-2-oxazolidinone copolymer substrates and improved acrylonitrile polymer compositions obtainable therewith



April 23, 1963 s. A. MURDOCK ETAL 3,086,959

GRAFT COPOLYMERS OF CERTAIN MONOMERIC SUL-FONIC ACID COMPOUNDS ONCERTAIN N-VINYL-Z-OXAZOLIDINONE COPOLYMER SUBSTRATES AND IMPROVEDACRYLONITRILE POLYMER COMPOSITIONS OBTAINABLE THEREWITH Filed Sept. 11,1959 Fi/amen/ous ar/ic/e compr/lseoofan acrg/oni/rf/e o/ymer ha /r 9ayra/f copo/ymer o amonomer/c orgap/c @Su on/c acjo r0) copo/ymergeaupon an N um -Z-0x0 ;o//'0/'none/v/ny/ /ac/0m capo ymer subs/ra/e Incapara/e0 fhere/n.

IN VEN TORS. 51 0/7/63 H. Mara o ck Teddy 6. Tr /0/' HTTORNEY UnitedStates Patent GRAFI CQPOLYMERS F CERTAEN MONG- MERIC SULFONIC AClDCOMPOUNDS 0N CER- TAIN .N-VINYL-Z-OXAZOLIDINONE COPOLY- MER SUBSTRATESAND IMPROVED ACRYLONI- TRILE POLYMER COMPOSITIONS OBTAINABLE TI-lliREWlTH Stanley A. Murdock, Rancho Cordova, Calif., and Teddy G.Traylor, Cambridge, Mass, assignors to The Dow Chemical Company,Midland,Mich., a corporation of Delaware Filed Septll, 1959, Ser. No.839,494 18 Claims; (Cl. 260-455) The presen't' invention resides in thegeneral field of organic chemistry and contributes specifically to thepolymet art, especially with respect to graft copolymer compositions:and fiber-forming polymer blends obtainable therewith. It isparticularly concerned with graft copolymersof certain monomericsulfonic acid compounds on preformed substrate copolymers ofN-vinyl-Z-oxazoli- 'dinones and N-vinyl lactams (hereinafter referred toas VO/YL copolymers) that have especial utility as dye-receptive,antistatic and stabilizing additaments for acrylon itrile polymercompositions which, advantageously, may be of the fiber-forming variety.The invention is also concerned With the compositions that may beobtained by blending the graft copolymers with acrylonitrile polymers,as well as with shaped articles which have been fabricated from suchcompositions and which, as a consequence, have significantly enhancedproperties and character istics' as regards improvements in and relatingto enhanced dye-receptivity, minimized inherent propensity to accumulateelectrostatic charges, natural stability to various deterioratinginfluences, including stability against becoming deleteriouslyinfluenced and degraded upon expo's'ur'e to heat at elevatedtemperatures and to light.

Within the scope and purview of the invention, there iscomprehended (1)the novel and utile graft copolymers of the indicated variety; (2) theadvantageous polyrner compositions, particularly fiber-formingcompositions, obtained by blending the graft copolymers withacrylonitrile polymers; (3) various shaped articles fabricated from" andcomprised of the graft copolymer-containing acrylonitril'e' polymercompositions; and (4) methods for the preparation of the above-indicatedcompositions.

It is the main purpose and primary design of the present invention toprovide and make available graft copolymers of certain monomericsulfonic acid compounds on VO/VL copolymers that are especially wellsuited for beinginco'rporated in acrylo'nitrile polymer compositions,particularly compositions of polyacrylonitrile, to serve in theindicated treble capacity of dye-assisting adjuvants, antistatic agentsand stabilizing ingredients. It is also a principal aim and chiefconcern of the invention to provide and make available acrylo'nitrilepolymer compositions and shaped articles therefrom that contain theaboveindicated and hereinafter more fully delineated type of graftcopolymeric add-itaments, which compositions have, as intrinsicdistinguishing characteristics, excellent receptivity of andacceptability for any of a wide variety of dyestuffs; permanently imbuedantistatic properties that are unusuallygood for and not commonlyencountered in polymeric materials of the synthetic, essentiallyhydrophobic varieties of such substances; and efficacious naturalstability to heat and light, as well as to certain chemical conditions,such as alkaline environments.

The graft copolymers of the present invention which have the indicatedcapacity and utility as additaments for acrylonitrile polymercompositions are comprised of (b) a preformed VO/VL copolymer trunk orbase substrate (as hereinafter more precisely delineated) on which thereis graft copolymerized a (a) monomeric, a-lkenyl group-con- "icetaining, organic sulfonic acid or derivative compound thereof that isselected from the group of such compounds (including mixtures thereof)consisting of those repre-' sented by the formulae:

all wherein X is hydrogen, a saturated aliphatic hydrocarbon radicalcontaining from 1 to 4 carbon atoms or' an alkali metal ion (includingsodium, potassium and lithium); Y is hydrogen, chlorine or bromine; R ismethyl or ethyl; Z is hydrogen or methyl; m has a numerical value inWhole number increments from 0 to 2;- n has a numerical value of l to 2;p is 0 or 1 and r is 1 to 4.

The polymer blend compositions of the present invention which fulfillthe above-indicated ends and offer corollary advantages and benefits,particularly as fiberforming compositions as will hereinafter bemanifest, are, in essence, comprised of an intimate and practicallyinseparable blend or alloy constitution of (A) an acrylonitrile polymerthat contains in the polymer molecule at least about percent by'wei'ghtof acrylonitrile which, preferably, is of the fiber-forming variety and,most advantageously, is polyac'rylonitrile but which, as indicated, maysuitably be a fiber-forming copolymer and (B) a minor proportion of theabove-indicated variety of beneficial graft copolyrneric additamentthatfunctions in the described manner.

The methods of the invention by which the herein contemplatedadvantageous compositions may be made involve preparation of the graftcopolymer, as well as incorporation of a minor proportion of the graftcopolymer product as a beneficial additament in and with theacrylonitrile polymer base by any of several beneficial techniques,hereinafter more thoroughly defined, adapted to suitably accomplish thedesired result.

Without being limited to or by the specific embodiments and modes ofoperation set forth, the invention is exemplified in and by thefollowing didactic illustrations wherein, unless otherwise indicated,all parts and percentages are to be taken on a weight basis.

ILLUSTRATION A Into a 5 liter reactorthat is equipped with an efficientagitator a nitrogen sparger, and a total reflux condenser, there ischarged about 370 grams of 47.36 percent aque ous solution of acopolymer of N-vinyl-S-methyl-Z-oxazolidinone (VO-M) andN-vinyl-2-pyrrolidone (VP) copolymerized in a 30:70 respective weightratio and hav-' ing a Fikentscher K-value of about 30. About 800milliliters of water is then added to the VO-M/VP copolymer solution.The resulting aqueous solution is brought to the boil and nitrogen isthen sparged into the reactor.

The nitrogen sparging is conducted throughout the ensuing reaction.

Over a three hour period, about 180 grams of a sodium styrene sulfonatemonomer dissolved in water to atotal volume of 2,000 ml. and 0.3 gram ofhydrogen peroxide dissolved in water to a total volume of 500 ml. arecontinuously pumped into the reactor. The sodium styrene sulfonatemonomer is about 41.6 percent active, as determined by bromination. Thebalance of the styrene sulfonate is substantially all sodium bromidewith a small quantity of sodium sulfate and a trace of polymer in themonomeric material.

After the entire quantities of the monomer and catalyst solutions arecharged to the reactor, the heating is continued and the temperature ofthe reaction mass is maintained at about 98 C. for an additional onehour period. The reaction is then terminated and the graftcopolymer-containing solution removed from the reactor. The polymerproduct is a clear, light brown solution that has a polymer content ofabout 7.8 percent. Upon analysis, about 95 percent of the sodium styrenesulfonate monomer is found converted to a graft copolymer product withthe VOM/ VP copolymer.

Polyacrylonitrile fibers containing about percent of the above graftcopolymer product, based on fiber weight (owf.), are prepared byimpregnating filamentary structures that are in aquagel condition (afterhaving been salt-spun and wet-stretched) in and with a dissolved aqueoussolution of the graft copolymer that contains about 3 percent (graft)copolymer solids. The polyacrylonitrile aquagel fiber is initiallyobtained by extruding a spining solution of fiber-formingpolyacrylonitrile comprised of about 10 parts of the polymer dissolvedin 90 parts of a 60 percent aqueous solution of zinc chloride through aspinnerette having 750 individual 6 mil diameter orifices into anaqueous coagulating bath that contains about 42 percent of dissolvedzinc chloride to form a multiple filament tow. After being spun, the towbundle of coagulated polyacrylonitrile aquagel fiber is washedsubstantially free from salt upon being withdrawn from the coagulatingbath and then wet-stretched for orientation to a total stretched lengththat is about thirteen times (13X) its original extruded length. Theaquagel fiber is then passed through the mentioned aqueous impregnatingbath of the dissolved graft copolymer additive so as to becomeimpregnated therewith to the indicated extent. The impregnating bath ismaintained at the boil and is simultaneously employed as a hotstretching medium for the aquagel fiber.

Following the impregnation, the aquagel fiber is irreversibly dried at150 C. to destroy the water-hydrated structure and convert'it to afinished fiber form. It is then heat set for five minutes at 150 C. Thefinally obtained 3 denier fiber product has a tenacity of about 4.0grams per denier, an elongation of about 29 percent, and a wet yieldstrength of about 0.9 gram per denier. The graft copolyrner-containingacrylonitrile polymer fiber product is found to have excellent naturalstability to heat and light as Well as against becoming degraded underthe influence of aqueous alkaline media at pH levels as high as 10. Itis found to be nearly free of propensity to accumulate charges of staticelectricity upon handling; being about commensurate at about 60 percentrelative humidity with viscose rayon fibers in this regard. As is widelyappreciated, viscose rayon is not considered to be afflicted to atroublesome degree with problems due to static.

In addition, the graft copolymer-containing sample has good color andhand and is dyeable with all classes of dyestuffs as applied undernormal dyeing conditions.

- The fiber product dyes well to deep and level shades of colorationwith Calcodur Pink 2BL, a direct type of dyestutf (Colour Index DirectRed 75) and Sevron Brilliant Red 4G, a basic dye formerly known as BasicRed 46 (Colour Index Basic Red 14).

The dyeing with Calcodur Pink ZBL is performed at the 4 percent levelaccording to conventional procedure in which the fiber sample ismaintained for about one hour at the boil in the dye bath which containsthe dyestufi in an amount equal to about 4 percent owf. The dyebath alsocontains sodium sulfate in an amount equal to about 15 percent owf. andhas a bath-to-fiber weight ratio of about 30:1, respectively. Afterbeing dyed, the fiber is rinsed thoroughly with water and dried forabout 20 minutes at C. The dye-receptivity of the Calcodur Pink 2BL-dyedfiber is then evaluated spectrophotometrically by measuring the amountof monochromatic light having a wave length of about 520 millimicronsfrom a standard source that is reflected from the dyed sample. Anumerical value on an arbitrarily designated:

scale from zero to one hundred is thereby obtained.- This valuerepresents the relative comparison of the amount of light that isreflected from a standard white tile reflector that has a reflectancevalue of 316 by extra-' Lower reflectance values are an indication ofbetter dye-receptivity in the fiber.- For example, a reflectance valueof about 20 or 25 to 50 or so for acrylonitrile polymer fibers dyed with4 percent Calcodur Pink 2BL is generally considered by those skilled inthe art to be representative of a degree of dye-- receptivity thatreadily meets or exceeds the most rigorous practical requirements and isordinarily assured ofreceiving general commercial acceptance andapproval; The 4 percent Calcodur Pink 2BL reflectance value of polationfrom the O-l00 scale.

the copolymer-containing fiber product is about 28.

The antistatic properties of the graft copolymer-con-- taining fiber arethen determined by measuring the electrical conductance of the fiberproduct at various humidities. As is also appreciated by those who areskilled in the art, the basis for such a test is that all fibers have atendency to generate static electricity upon being handled. Only thosethat are possessed of suflicient electrical conductance to dissipate thecharge as quickly as it forms are not hampered by the bothersome effectsof electricity. Thus, a measure of the electrical conductance of a fiberis a good indication of its ability to dissipate static electricity. Theconductivities of the various fiber samples tested are found bydetermining their electrical resistances. Resistance, of course, is thereciprocal quantity of conductivity. In order to permit various fibersamples to be compared on a common basis, the conductivities of thesamples tested are actually measured as volume resistivities accordingto the following formula:

Volume resistivity (Resistance) (Cross-sectional area) The units ofvolume resistivity are ohm-cmP/cm.

Prior to being tested, the graft copolymer-containing polyacrylonitrilefiber prepared in the indicated manner is vat dyed in the conventionalmanner with Cibanene Green BF Dbl. Paste (Colour Index Vat Green No. l).A portion of the vat dyed sample is then subjected to fifteen (15)consecutive No. 3A accelerated wash tests in accordance with theAmerican Association of Textile Chemists and Colorisrts (AATCC) Manual.The actual resistivities of the merely vat dyed sample as well as thatof the sample that is both vat dyed and wash tested are then determinedafter the samples being tested are conditioned for seventy-two hours atthe particular temperature and relative humidity conditions involved ineach of the tests) by tautly connecting a web-like sample of the yarnbetween two electrodes, each of which are 9 centimeters long spacedparallel 13 centimeters apart, and across which there is applied a 900volt direct current potential. For purposes of comparison, the volumeresistivities of cotton, wool and an unmodified polyacrylonitrile fiber(obtained in the same way as the copolymer-containing fiber but withouthaving the polymeric additament incorporated therein) are also tested inthe indicated manner along with the graft copolymer-containing fiber inaccordance with the present invention.

The results are set forth in the following tabulation which indicatesthe volume resistivities obtained at various relative humidities (RI-I.)at 23 C. of each of the samples tested.

Table 1 VOLUME RESISTIVITIES OF VARIOUS FIBER SAMPLES COMPARED TOP-OLYAORYLONITRILE FIBERS IMPREG- NATED WITH GRAFI COPOLYMER OF SODIUMSTYRENE SULFONATE ON VO-M/VP COPOLYMER SUBSTRATE As is apparent in theforegoing, the graft-copolymercontaining sample, even after beingseverely washed, has electrical conductance properties much superior toordinary polyaorylonitrile and only slightly poorer than cotton. At thesame time, the physical proper-ties of the copolymer-containing fiberare excellent, being about equal to those of the unmodifiedpolyacrylonitrile fiber.

In contrast with the foregoing, a polyacrylonitrile fiber prepared inthe above-indicated manner so as to be im pregnated while in the aquagelform with a mere physical mixture of the same VO-M/ VP copolymer and thehemppolymer of sodium styrene sulfonate produced a fiber has a veryharsh feeling and an undesirable hand. When this fiber sample whichcontains the mere physical mixture of the VO-M/VP copolymer and thesodium styrene sulfonate homop'olymer is subjected to severe washing andv-at dyed in general accordance with the foregoing procedure, its volumeresistivity characteristics and static properties are about the sameupon testing as those indicated in the above table for unmodifiedpolyacrylonitrile.

ILLUSTRATION B Using the same apparatus as described in Illustration A,about 1000 grams of a 30 percent aqueous solution of the same VO-M/VPcopolymer is charged to the reactor. The VO-M/ VP copolymer solution isthen brought to the boil, at which point nitrogen spa-rging is commencedand continued throughout the entire run. About 400 gnams of 50 percentactive sodium styrene sulfonate monomer, dissolved in water to a totalvolume of about 2670 1111., and 0.1 gram of hydrogen peroxide, dissolvedin water to a total volume of 272 oil, are continuously metered into thehot VO-M/VP copolymer solution in the reactor over a 3-hour period.After the addition of the aqueous solutions of monomer and catalyst arecompleted, the charge in the reactor is held at the boil for about 2hours. At the termination of the polymerization reaction which occurs,the graft copolymer-containing reaction mass is drained and a clear,brown polymer solution is obtained. The conversion of monomer to graftpolymer is found to be about 56 percent. The product solution is foundto contain about 14 percent of dissolved graft copolymer solids, inwhichthe ratioof VO-M/VP copolymer to sodium styrene sulfonate graftcopolymerized thereon is found to be on the order of about 7 2128,respectively.

A solution of about 3 percent of the gnaft copolymer is prepared toimpregnate a polyaorylonitrile aquagel fiber in a manner similar to thatset forth in Illustration A. The impregnation of the copoiymericadditament is accomplished during the stretch drawing of the aquagel inthe second stage of the physical extension operation by means of whichthe fiber is oriented and While it is immersed in the hot graftcopolymer solution. The total stretching of the aquagel is performed ina four stage operation. In the first stage, the aquagel is coldstretched with a stretch ratio of about 1.56:1. The initial coldstretching is followed by three hot stretch stages (the first of whichis the abovementioned stage in which the impregiation is accomplished)wherein the sequential stretches imposed are on the order of 3.89 times;1.89 times; and 1.20 times their initial length prior to stretchingrespectively. After being impregnated with the copolymer, the aquagelfiber is dried at about C. It is found to contain about 3.5 percent ofthe polymeric additament intimately incorporated therein.

The gr-aft copolymer-containing fiber has good color, excellent hand andis' dyeable with all classes of dyes at normal dyeing conditions. Itsstability to light, heat and alkaline media having a pH as high as 10are excellent. Its physical properties are about as follows:

Denier 3.

Tenacity 2.5 grams per denier. Elongation 29 percent.

Dry yield strength 0.8 gram per denier. Wet yield strength 0.55 gram perdenier.

The volume resistivities under various conditions of relative humidityat 23 C. of the graft copolymer-eontaining fiber product are determinedin the manner set forth in Illustration A after a portion of the fiberhas been vat dyed with Cibanone Green BF, Dbl. Paste and a portion.ofthe vat dyed fiber is subjected to jive (5) No. 3- A accelerated washtests, The values found for the vat dyed fiber are about 1.6)(10ohm-cmP/cm. at 47 percent RH. and about 8 .4 10 ohm-crnF/orn. at 66percent RH. The values for the vat dyed and Wash tested sample are about1.4 10 ohm-cmflcm. at 47 percent RH. and about 1.2 10 ohm-cmF/cm. at 66percent R.H. The superiority in antistatic properties of the graftcopolymer-containing fiber, even after severe scouring, dyeing andwashing treatments, is evidenced by comparison of the foregoing volumeresistivity values with those obtained under the same conditions forcotton; wool and unmodified polyacrylonitrile fibers, as are set forthin the preceding Table '1.

ILLUSTRATION C The general procedure of the foregoing eXam-ples isemployed to prepare a graft copolymer from the following charge which ispolymerized for about 16 hours at a temperature of 50 C.:

Grams Sodium vinyl benzyl sulfonate 1.5 30/70 VO-M/VP copolymer (K40)1.5 Water 12.0 Potassium persul-fate 0.03

static characteristics, satisfactory stability and suitable physicalproperties.

ILLUSTRATION D Following the procedure of Illustration C, graft coipolymer products are obtained from each of the following charges:

The product is a slightly colored solution. It contains a graftcopolymer of about 70 percent VO-M/VP copolymer upon which there isgraft copolymerized about 30 percent of the taurine. The nomenclaturetaurine, incidentally, is commonly employed to designate Z-aminoethanesulfonic acid.

BATCH D2 2-sulfoethyl acrylate, sodium salt "grams--. 1.1 30/70 VO-M/VPcopolymer (K25) do 2.6 Water ml 15.2 Potassium persulfate grarn 0.02 pHof charge 8.5 Conversion of monomer to graft copolymer percent 90 Thedissolved graft copolymer solution that is obtained as a product has aslight yellow coloration. The composition is about 75 percent VO-M/VPcopolymer and 25 percent graft copolymerized sodium 2-sulfoethylacrylate.

BATCH D3 2-sulfoethyl methacrylate, sodium salt grams 1.1 50/50 VOM/VPcopolymer (Kl-35) ..do 2.6 Water ml 15.2 Potassium persulfate gram 0.02pH of charge 8.5

Conversion of monomer to graft copolymers percent 90.5

The product graft copolymer solution has a slight yellow color. Thecomposition of the graft copolymer is about 72 percent VO-M/ VP and 28percent graft copolymerized sodium Z-sulfoethyl methacrylate.

BATCH D-4 Sodiumstyrene sulfonate "grams", 6.0 15/85 VO-M/VP copolymer(K-22) do 6.0 Water do 48.0 Potassium persulfate do 0.12 pH of charge2.0

Conversion is about 90 percent with the product obtained being a clear,colorless solution.

Excellent results commensurate with those set forth in the first threeillustrations, are obtained when each of the above graft copolymerproducts is incorporated in polyacrylonitrile fibers following theprocedure set forth in the first illustration. Excellent results arealso obtained when the foregoing general procedure is repeated toprepare graft copolymers upon identical or similar VO-M/VP copolymers of.allyl taurine; sodium salt; graft copolymers upon identical or similarVO-M/VP copolymers of allyl propene sulfonic acid; and graft copolymersupon identical or similar VO-M/VP copolymers of the sodium salt ofethylene sulfonic acid with each of the graft copolymer products havingcompositions equivalent to those described.

Excellent results may also be obtained when the foregoing is repeated toprepare graft copolymer additives from other VO/VL copolymer substrates,such as copolymers of N-vinyl-S-ethyl-2-oxazolidinone and VP; copolymersof N-vinyl-Z-oxazolidinone and VP; copolymers of VO-M and N-vinylcaprolactam; copolymers of VO-M and N-vinyl-piperidone; and so forth.

Results similar to those set forth in the foregoing can likewise beobtained when the graft copolymer additaments are incorporated inpolyacrylonitrile and other acrylonitrile polymer fibers to providearticles in accordance with the present invention by blending or mixingtogether the graft copolymer and the fiber-forming acrylonitrile polymerin a spinning composition or dope prior to its extrusion intofilamentary products by either wet spinning or dry spinning techniques.in such instances, incidentally, it may be desirable, in order :tosecure optimum benefit in the practice of the invention, to employrelatively larger quantities of the graft copolymeric additament thanwhen surface impregnation is performed so that the presence of effectivequantities of the additament at or near the peripheral portion of thearticle is assured.

Besides those specifically illustrated herein, other organic sulfonicacid compounds may also be utilized for the preparation of the graftcopolymer products of the present invention such, by way ofillustration, as those which are set forth in the disclosure of UnitedStates Letters Patent Number 2,527,300. In addition to the copolymersspecifically described in the foregoing examples, other copolymericadditaments that may advantageously be employed in the practice of thepresent invention include graft copolymers on the indicated preformedVO/VL polymer substrates of such organic sulfonic acid compounds asZ-propene sulfonic acid; sodium para-vinylbenzene sulfonate; 2- and/or3-sulfopropyl acrylate, asulfoacrylic acid; sodium vinyl toluenesulfonate; potas sium ortho-chlorostyrene sulfonate;2-hydroxy-3-sulfopropyl acrylate, sodium salt; sodium3-alloxyl-2-hydroxypropane sulfonate, 4-sulf0phenyl acrylate, sodiumsalt; N-allyl imino di-(Z-ethane sulfonic acid); and the like.

Still other organic sulfonic acid compounds that may be employed are asset forth in the following representative, but by no means exhaustive,listing wherein they are grouped according to the above designatedtypes.

Aromatic alkenyl-containing sulfonic acid compounds (Formula I):

Para-styrene sulfonic acid Ortho-styrene sulfonic acid Para-isopropenylbenzene sulfonic acid Para-vinylbenzyl sulfonic acid Ortho-isopropenylbenzyl sulfonic acid Sodium para-styrene sulfonate VPotassiumortho-styrene sulfonate Methyl para-styrene sulfonate Ethylpara-vinylbenzyl sulfonate Ortho-vinyl benzyl sulfonic acid Is-opropylortho-isopropenyl benzene sulfonate n-Butyl ortho-styrene sulfonateTertiary butyl para-styrene sulfonate 2-chloro-4-viny1 benzene sulfonicacid 4-bromo-2-isopropenyl benzene sulfonic acid 3-vinyl toluene6-sulfonic acid, sodium salt 2-ethyl-4-Vinyl-benzene sulfonic acid2,3-dichloro-4-vinyl benzene sulfonic acid 2,3,5-tribromo-4-vinylbenzene sulfonic acid 2-chloro-3-vinyl toluene-6-sulfonic acid2,3-diethyl-4-vinyl-benzyl sulfonate, sodium salt Alkenyl sulfonic acidcompounds (Formula II):

Ethylene sulfonic acid Sodium ethylene sulfonate Potassium ethylenesulfonate Methyl ethylene sulfonate Isopropyl ethylene 'sulfonatel-propene 3-sulfonic acid l-propene l-sulfonic acid, sodium saltl-propene 2-sulfonic acid, ethyl ester Z-butylene 4-sulfonic acid,n-butyl ester l-butylene 3-su1fonic acid Tertiary butylene sulfonic acidSulfoalkylacrylate compounds (Formula III):

Sulfomethylacrylate 2-sulfoethylacrylate Sulfomethylmethacrylate, sodiumsalt 2-sulfoethylmethacrylate, methyl ester 2-sulfoethylmethacrylate,potassium salt Acryloyl taurine and homolog compounds (Formula. IV):

N-acryloyl taurine N-acryloyl taurine, sodium salt N-methacryloyltaurine, methyl ester N-rnethacryloyl taurine, potassium salt N-acryloyltaurine, ethyl ester N-acryloyl-aminomethane sulfonic acidN-methacryloyl-aminomethane sulfonic acid, sodium salt MethylN-methacryloyl-aminomethane sulfonate Allyl taurine and homologcompounds (Formula V):

Allyl taurine Allyl taurine, sodium salt Allyl taurine, potassium saltMethallyl taurine Methallyl taurine, methyl ester Methallyl taurine,isopropyl ester N-allyl-aminomethane sulfonic acid SodiumN-allyl-aminomethane sulfonate Lithium N-methallyl-aminomethanesulfonate n-Butyl N-allyl'-aminomethane sulfonate V The copolymers ofN-vinyl-Z-oxazolidinones (i.e., VOs) n and N-vinyl lactams (i.e., VLs)that are utilized as preformed substrates in the preparation of thegraft copolymeric additaments of the present invention are copolymers of(1) between about 10 and about 90 weight percent, based on the weight ofthe copolymer molecule, advantageously between about 40 and 60 weightpercent, of polymerized N-vinyl-Z-ox-azolidinone and (2) between about90 and 10 weight percent, based on the weight of the copolymcr molecule,advantageously between about 60 and 40 weight percent, of polymerizedN-vinyl lactam. The monomeric N-vinyl-2-oxazolidinones employed forpreparation of the VO/VL copolymer substrate are of the generalstructure:

wherein each R is independently selected from the group consisting ofhydrogen, alkyl radicals, and haloalkyl radicals of from 1 to about 4carbon atoms, and aryl radicals of from 6 to about 10 carbon atoms.Advantageously, ring-substituted N-vinyl-2-oxazolidinones are employed,particularly those having a single alkyl or aryl substituent in the-position of the ring such as N-vinyl- 5 niethyl-Z-oxazolidiuone (VO-M);N-vinyl-S-ethyl-Z- oxazolidinone (VO -E);N-vinyl-5-phenyl-2-oxazolidinone (VO-P); and so forth. Of course, ifdesired, non-ringsubstituted N-vinyl-Z-oxazolidinone may also beemployed.

The N-vinyl lactam monomers that are utilized in the preparation of thepreformed VO/VL copolymer substrates may be only of those (or theirmixtures) which are variously characterized and generically known to theart as N-vinyl lactams or l-vinyl lactams. Such monomers are disclosedand contemplated in United States Letters Patents Nos. 2,265,450;2,371,804; and 2,335,454. Beneficially, the N-v-inyl lactams that areemployed are N- vinyl-2-pyrrolidone (VP), also known asN-vinyl-Z-pyrrolidinone; N-vinyl-piperidone (VPip); N-vinyl caprolactam(VC); N-vinyl-S-methyl-2-pyrrolidone (VP-M); and the like, particularlyVP.

It is desirable for the VO /VL copolymer that is used to be awater-soluble material. In cases where certain ring-substituted VOs areemployed, such as VO-M,

VO-E and VO-P, it is generally beneficial for the copoly mer to containat least about 40 weight percent of the VL copolymerized therein.Copolymers having substantially less VL may tend to water-insolubilityand make it necessary to work with a product that may have a cloud (orprecipitation) point in water or other aqueous solution beneath theboil. Copolymers containing from about 10 to about 60 weight percent VO-are generally watersoluble at normal room temperatures (i.e., 2025 C.)at solution concentrations as great as 20-30 weight percent, andfrequently greater.

These N-vinyl-Z-oxazolidinon'e copolymers and their preparation arediscussed in US. Patents 2,946,772, filed February 27, 1958, and2,948,708 filed April 3, 1958.

The graft copolymer products of the present invention may generally beprepared by methods of polymerization, such as those which have beendemonstrated in the foregoing exemplifying illustrations, that employsuch polymerization catalysts as persulfates, organic and inorganicperoxide and azo type materials in quantities that are conventional forsuch uses. The graft copolymers may oftentimes be prepared bypolymerizing the monomeric constituent onto the preformed polymersubstrate under the influence of high energy irradiation such as bymeans of X-rays and the like, or simply by heating or evaporating themonomer-containing polymerization" mixture. The graft copolymers may beprepared in both aqueous and organic solvent vehicles using temperaturesfor the desired polymerization that may vary from about room temperatureto the boiling point of the polymerization mixture. It is ordinarilysatisfactory to conduct the reaction at a temperature of about 50 to orC; Usually, depending on the specific factors that may be involved, thegraft copolymerization may be accomplished satisfactorily within a timeperiod of about 5 to 60 hours.

The compositions of the graft copolymer can vary with in rather widelimits. The content of the monomeric constituent that is graftcopolyrnerized on the preformed polymer substrate may advantageously bebetween about 12 and about 80 weight percent of the resulting graftcopolymer product and, more advantageously, between about 30 and 60weigh-t percent. In many cases, especially to secure optimumdye-receptivity, nearly equivalent or about commensurate or equal weightproportions of the preformed polymer substrate and the monomericconstituent graft copolymerized thereto may be employed with benefit inthe preparation of the graft copolymeric additaments.

The polymerization system that is employed for the preparation of thegraft copolymers of the present invention may consist of as much as 50percent by weight of the mixture of monomers and preformed polymersubstrate to vbe polymerized in the aqueous or other medium. The amountof polymeriza-ble constituents that are provided in the graftcopolymerization system may be influenced somewhat by the manner inwhich it is intended to incorporate the product in the synthetic polymercompositions in order to provide the graft copolymer-contain ingacrylonitrile polymer compositions of the invention.

If, for example, it is intended to incorporate the graft copolymerproducts by blending into a fiber-forming composition prior to itsfabrication into shaped articles, the polymerization system may, ifdesired, contain about equal proportions by weight of the chargedpolymerizing constituents and the polymerization medium which,preferably, is miscible with and tolerable in the spinning solutionsolvent intended to be used. In such cases, the graft copolymer productmay ordinarily be readily isolated from unreacted monomer and directlyincorporated in the fiber-forming composition. If the incorporation ofthe graft copolymer in a fiber-forming composition is to be achieved byimpregnation therewith of an already-formed shaped article of thecomposition, it may be desirable to effect the graft coplymerization soas to directly form a. suitable applicating solution (or suspension inthe cases aosaeso where a non-solvent polymerization vehicle isemployed) of the graft copolymer product. For such purposes, thepolymerization system may be prepared to contain as little as 2 or 10percent by weight of the polymerized monomeric and polymericingredients. Such a method for preparing the graft copolymers may beespecially appropriate when they are intended, in the practice of thepresent invention, to be applied to acrylonitrile polymer fibers and thelike that are derived from aquagels in the course of their manufacture,such as the acrylonitrile polymer fibers that are wet spun from aqueoussaline solutions of the fiber-forming polymer.

' In such instances, as has been demonstrated, the graft copolymericadditament may be impregnated into the fiber from aqueous solution:while the fiber is in a swollen or gel condition, as apolyacrylonitrile fiber in an aquagel condition, in order to obtain thedesired copolymer-containing product.

If desired, the graft copolyrner-containing acrylonitrile polymercompositions may comprise as much as 20 or more weight percent of thegraft copolymeric additament, based on the weight of the composition.Usually, however, suitable properties and characteristics and betterfiber-forming properties in a given composition may be achieved whenlesser proportions of the graft copolymeric additament are incorporatedtherein. An appreciable improvement in dye-receptivity, antistaticproperties and stability may frequently be obtained When a quantity ofthe copolymeric additament that is as small as 2 (and even as low as lor less) weight percent is employed. Advantageously, an amount betweenabout 6 and 12 weight percent of the copolymeric additament may thus beutilized in the composition. Greater advantages may often accrue whenthe amount of the copolymeric additament that is incorporated in thecomposition is in the neighborhood of -10 weight percent, based on theweight of the composition.

' As has been indicated, the graft copolymeric additaments may beincorporated in or physically together with the acrylonitrile polymercompositions according to various techniques. Thus, for example, thecopolymeric additament and the acrylonitrile polymer may be directlyblended in order to provide the composition which, incidentally, may beused for any desired fabrication purpose in addition to fiber-formingand the like. Beneficially (particularly should insoluble or partiallyinsoluble products be involved), the polymers may be comminuted, eitherseparately or in combination, before being intimately blended togetherby mechanical or other means. The blended polymers may be prepared intosuitable fiberforming systems by dissolving or otherwise dispersing themin a suitable liquid medium. Or, the compositions may be provided infiber-forming systems by seqentially dispersing the polymers in anydesired order in a suitable medium, as by incorporating the copoly-mericadditament in a prepared acrylonitrile polymer spinning solution, dopeor the like.

As is evident from the illustrations heretofore included, a highlyadvantageous technique for providing the compositions, particularly whenacrylonitrile polymer fiber products are involved, is to apply orimpregnate the copolymeric additament from an aqueous dispersion thereofto a shaped acrylonitrile polymer article that is in an aquagelcondition in a known manner. Thus, an acrylonitrile polymer filamentaryarticle that has been spun from an aqueous saline spinning solution maybe conveniently passed, after its coagulation and while it is in anaquagel condition, through a Water bath containing the dissolved graftoopolymeric additament in order to impregnate the filament with thegraft copolymer and provide a composition and an article in accordancewith the invention. In addition, as has been demonstrated in theexamples, in situ polymerization techniques may also be relied upon toprovide the copolymeric additament in the 12 acrylonitrile polymers ineither fabricated or unfabricated form.

The compositions of the invention may advantageously be utilized in orwith fiber-forming systems of any desired type in order to providefibers and the like according to procedures and techniques that areconventionally employed for such purposes in the preparation of fiber-sand such related shaped articles as filaments, strands, yarns, tows,threads, cords and other funicular structures, ribbons, tapes, films,foils, sheets and the like which may be manufactured from syntheticpolymeric materials. It is frequently desirable to employ concentratedsolutions of salts or mixtures of salts as the dispersing or dissolvingmedia for such purposes. Such solutions may, as has been indicated,contain at least about 55 percent by weight, based on the weight of thesolution, of zinc chloride or other known aqueous saline solvents forthe polymer. Acrylonitrile polymer fiber products that are spun fromsaline fiber-forming systems may, by Way of further illustration, becoagulated in more dilute aqueous saline solutions of a like or similarnature and may then be processed after coagulation according toconventional techniques of washing, stretching, drying, finishing andthe like with the modification of the present invention beingaccomplished prior or subsequent to the spinning as may be desired andsuitable in particular instances.

The acrylonitrile polymer fiber products in accordance with the presentinvention (one of which is schematically illustrated in the sole figureof the accompanying drawing) have excellent physical properties andother desirable characteristics for a textile material and have a highcapacity for and are readily and satisfactorily dyeable to deep andlevel shades with any of a wide variety of dyestuffs. For example, theymay be easily and successfully dyed according to conventional proceduresusing acid, vat, acetate, direct, naphthol, basic and sulfur dyes. I

Such dye-stuffs, by way of didactic illustration, as Calcocid AlizarineViolet (Colour Index 61710, formerly Colour Index 1080), SulfanthreneRed 3B (Colour Index Vat Violet 2) Amacel Scarlet GB (Colour IndexDirect Red 1 also known as Amacel Scarlet BS, and having AmericanPrototype Number 244), Calcodur Pink TBL (Colour Index 353, also morerecently, Colour Index Direct Red 75) Naphthol ASMX (Colour Index35527), East Red TRN Salt (Colour Index Azoic Diazo Component 11), andImmedial Bordeaux G (Colour Index Sulfur Brown 12) may advantageously beemployed for such purposes.

Other dyestuffs, by way of further illustration, that may be utilizedbeneficially on the graft copolymer-containing acrylonitrile polymerblended fiber products of the invention include such direct cotton dyesas Chlorantine Fast Green SBLL (Colour Index Direct Green 27),Chlorantine Fast Red 7B (Colour Index Direct Red 81), Pontamine Green GXConc. 135 percent (Colour Index Direct Green 6), Calcomine Black EXNConc. (Colour Index Direct Black 38), Niagara Blue NR (Colour IndexDirect Blue 151) and Erie Fast Scarlet 4BA (Colour Index Direct Red 24);such acid dyes as Anthraquinone Green GN (Colour Index Acid Green 25),Sulfonine Brown 2R (Colour Index Acid Orange 51) Sulfonine Yellow 2G(Colour Index Acid Yellow 40), Xylene Milling Black 2B (Colour IndexAcid Black 26A), Xylene Milling Blue FF (Colour Index Acid Blue 61),Xylene Fast Rubine 3GP PAT (Colour Index Acid Red 57),

Calcocid Navy Blue R Conc. (Colour Index Acid Blue C-alcocid Fast BlueBL (Colour Index Fast Blue 59), Calcocid Milling Red 3R (Col-our IndexAcid Red 151), Alizarine Levelling Blue 2R (Colour Index Acid Blue 51),Amacid Azo Yellow' G Extra (Colour Index Acid Yellow 63); suchmordant-acid dyes as Alizarine Light Green GS (Colour Index Acid Green25); such basic dyes as Brilliant Green Crystals (Colour Index BasicGreen 1), and Rhodamine B Extra S (Colour Index 13 Vat Blue 35); suchvat dyestuffs as Midland Vat Blue R Powder (Colour Index Vat Blue 35),sulfanthrene Brown G Paste (Colour Index Vat Brown Sulfanthrene Blue 2BDbl. Paste (Colour Index Vat Blue 5), and Sulfanthrene Red 3B Paste(Colour Index Vat Violet 2); various soluble vat dyestuffs; such acetatedyes as Celliton Fast Brown 3RA Extra CF (Colour Index Dispersed Orange5), Celliton Fast Rubine BA CF (Colour Index Dispersed Red 13), ArtisilDirect 3BP and Celanthrene Red 3BN Conc. (Both Colour Index DispersedRed 15), Celanthrene Pure Blue BRS 400 percent (Colour Index DispersedBlue 1) and Acetamine Yellow N (Colour Index Dispersed Yellow 32);B-Naphthol 2-chloro-4-nitroaniline, and azoic dye; such sulfur dyes asKatigen Brilliant Blue GGS High Conc. (Colour Index Sulf. Blue 9) andIndo Carbon CLGS (Colour Index Sulf. Blue 6); and various premetallizeddyestuffs.

The dyed products are generally lightfast and stable to heat and areWell imbued with a good resistance to crocking. In addition, the dyedproducts exhibit good wash-fastness and retain the dye-assistingcopolymeric additament in a substantially permanent manner, despiterepeated exposure and subjection to washing, laundering and dry cleaningtreatments. 1

What is claimed is:

1. Graft copolymer of between about 10 and about 80 weight percent of(a) an alkenyl group-containing organic sulfonic acid compound selectedfrom the group consisting of those represented by the formulae:

CHz=C (CH2) D-SOZX CHz=C H- (0 H2) iii-S 03X all wherein X is selectedfrom the group consisting of hydrogen, saturated aliphatic hydrocarbonradicals containing from 1 to 4 carbon atoms and alkali metals; Y isselected from the group consisting of hydrogen, chlorine and bromine; Ris selected from the group consisting of methyl and ethyl; Z is selectedfrom the group consisting of hydrogen and methyl, m is an integer from 0to 2; n is an integer from 1 to 2; p is an integer from 0 to 1, and r isan integer from 1 to 4; and (b) from about 90 to about 20 weight percentof a copolymer of a N-vinyl-2-oxazolidinone and a N-vinyl lactam, saidcopolymer being from about 10 to about '90 weight percent, based oncopolymer weight, of a N-vinyl-Z-oxazolidinone monomer copolymerizedwith from about 90 to about 10 weight percent, based on copolymerweight, of a N-vinyl lactam monomer.

2. The graft copolymer of claim 1, containing in the polymer molecule,in polymerized form, between about 30 and about 60 weight percent ofsaid organic sulfonic acid compound as graft copolymerized substituentson said N-viny1-2-oxazolidinone/N-Vinyl lactam copolymer.

3. The graft copolymer of claim 1, wherein said copolymer is a copolymerof N-vinyl-S-methyl-Z-oxazolidinone and N-vinyl-2-pyrrolidone.

4. Method for the preparation of a graft copolymer which comprisespolymerizing between about 10 and about 80 Weight percent, based onresulting graft copolymer weight of an alkenyl group-containing organic14 sulfonic acid compound selected from the group consisting of thosehaving the formulae:

2 (VI) all wherein X is selected from the group consisting of hydrogen,saturated aliphatic hydrocarbon radicals containing from 1 to 4 carbonatoms and alkali metals; Y is selected from the group consisting ofhydrogen, chlorine and bromine; R is selected from the group consistingof methyl and ethyl; Z is selected from the group consisting of hydrogenand methyl; m is an integer from 0 to 2; n is an integer from 1 to 2; pis an integer from 0 to 1; and r is an integer from 1 to 4; with betweenabout 9'0 and about 20 weight percent of a copolymer of a N-vinyl-2-oxazolidinone and a N-vinyl lactam, said copolymer being fromabout 10 to about 90 weight percent, based on copolymer weight, of aN-vinyl-Z-oxazolidinone monomer eopolymerized with from about 90 toabout 10 weight percent, based on copolymer weight, of a N- vinyl lactammonomer.

5. Composition comprising a major proportion of at least about weightpercent, based on composition weight, of (A) a polymerized ethylenicallyunsaturated monomeric material containing at least about 80 weightpercent of polymerized acrylonitrile, and (B) a minor proportion of upto about 20 weight percent, based on the composition weight, of a graftcopolymer of (a) between about 10 and about 80 weight percent of analkenyl group-containing organic sulfonic acid compound selected fromthe group consisting of those having the formulae:

all wherein X is selected from the group consisting of hydrogen,saturated aliphatic hydrocarbon radicals containing from 1 to 4 carbonatoms and alkali metals; Y is selected from the group consisting ofhydrogen, chlorine and bromine; R is selected from the group consistingof methyl and ethyl; Z is selected from the group consisting of hydrogenand methyl; m is an integer from 0 to 2; n is an integer from 1 to 2; pis an integer from 0 to 1; and r is an integer from =1 to 4; and (b)from about to about 20 weight percent of a copolymer of a N-vinyl-2-oxazolidinone and a N-vinyl-lactam, said copolymer being fromabout 10 to about 90 weight percent, based on copolymer weight, of aN-vinyl-2-oxazolidinone monomer copolymerized with from about 90 toabout 10 weight percent, based on copolymer weight, of a N-vinyl lactammonomer.

6. The composition of claim 5 containing between about 6 and about 12weight percent, based on composition weight, of said graft copolymer.

7. The composition of claim 5, wherein said graft copolymer contains, inpolymerized form, between about 30 and about 60 weight percent of saidorganic sulfonic acid compound as graft copolymerized substituents onsaid N-vinyl-2-oxazolidinone/N-vinyl lactam copolymer.

8. The composition of claim 5, wherein the graft copolymer is sodiumstyrene sulfonate and a copolymer of N-vinyl-5-methyl-2-oxazolidinoneand N-vinyl-Z-pyrrolidone that is water-soluble at about C.

9. The composition of claim 5, wherein the graft copolymer issodium-Z-sulfo ethyl methacrylate and a copolymer ofN-vinyl-S-methyl-2-oxazolidinone and N- vinyl-2-pyrrolidone that isWater-soluble at about 20 C.

10. The composition of claim 5, wherein the graft copolymer is sodiumvinyl benzyl sulfonate and a copolymer ofN-vinyl-S-methyl-Z-oxazolidinone and N-vinyl-Z-pyrrolidone that iswater-soluble at about 20 C.

11.,The composition of claim 5, wherein the graft copolymer is acryloyltaurine, sodium salt and a copolymer of N-vinyl-S-methyl-Z-oxazolidinoneand N-vinyl-Z-pyrrolidone that is water-soluble at about 20 C.

12. The composition of claim 5, wherein the graft copolymer is sulfopropyl acrylate, sodium salt and a copolymer ofN-vinyl-S-methyl-2-oxazolidinone and N- vinyl-2-pyrrolidone that iswater-soluble at about 20 C.

13. The composition of claim 5, wherein the acrylonitrile polymer ispolyacrylonitrile.

14. The composition of claim 5 dispersed in a solvent forpolyacrylonitrile.

15. A filamentary shaped article comprised of the composition of claim5.

16. Method for the preparation of a dye-receptive, antistatic,synthetic, linear, hydrophobic polymer composition which comprisesmixing together a minor proportion of up to about 20 weight percent,based on composition weight, of 1) a graft copolymer of (a) betweenabout 10 and about 80 weight percent of an alkenyl group-containingorganic sulfonic acid compound selected from the group consisting ofthose having the formulae:

all wherein X is selected from the group consisting of hydrogen,saturated aliphatic hydrocarbon radicals containing from 1 to 4 carbonatoms and alkali metals; Y is selected from the group consisting ofhydrogen, chlorine and bromine; R is selected from the group consistingof methyl and ethyl; Z is selected from the group consisting of hydrogenand methyl; m is an integer from 0 to 2; n is an integer from 1 to 2; pis an integer from 0 to 1; and r is an integer from 1 to 4; and (b) fromabout 90 to about 20 weight percent of a copolymer of aN-vinyl-Z-oxazolidinone and a N-vinyl lactam, said graft copolymer beinga copolymer of from about 10 to about 90 weight percent, based oncopolymer weight, of a N-vinyl-2-oxazolidinone monomer copolymerizedwith from about 90 to about 10 Weight percent, based on copolymerweight, of a N-vinyl lactam monomer, with (2) a polymerizedmonoethylenically unsaturated monomeric material containing at leastabout weight percent of polymerized acrylonitrile.

17. Method for the preparation of a dye-receptive, antistatic,synthetic, linear hydrophobic polymer composition which comprisesimmersing an aquagel of a polymerized ethylenically unsaturatedmonomeric material containing at least about 80 weight percent ofpolymerized acrylonitrile in the form of a shaped article into anaqueous dispersion of a graft copolymer of (a) between about 10 andabout 80 weight percent of an alkenyl group-containing organic sulfonicacid compound selected from the group consisting of those having theformulae:

all wherein X is selected from the group consisting of hydrogen,saturated aliphatic hydrocarbon radicals containing from 1 to 4 carbonatoms and alkali metals; Y is selected from the group consisting ofhydrogen, chlorine and bromine; R is selected from the group consistingof methyl and ethyl; Z is selected from the group consisting of hydrogenand methyl; m is an integer from 0 to 2; n is an integer from 1 to 2; pis an integer from 0 to 1; and r is an integer from 1 to 4; and (b) fromabout to about 20 weight percent of a copolymer of a N-vinyl-Z-oxazolidinone and a N-vinyl lactam, said copolymer being fromabout 10 toabout 90 weight percent, based on copolymer weight, of aN-vinyl-Z-oxazolidinone monomer copolymerized with from about 90* toabout 10 weight percent, based on copolymer weight, of a N-vinyl lactammonomer, until between about 2 and about 20 weight percent of said graftcopolymer, based on resulting dry composition weight, is impregnated insaid aquagel; and irreversibly drying said graft copolymer-containingaquagel to convert it from the aquagel condition to a finished shapedarticle form.

18. The method of claim 17, wherein said acrylonitrile polymer ispolyacrylonitrile.

References Cited in the file of this patent UNITED STATES PATENTS

1. GRAFT COPOLYMER OF BETWEEN ABOUT 10 AND ABOUT 80 WEIGHT PERCENT OF(A) AN ALKENYL GROUP-CONTAINING ORGANIC SULFONIC ACID COMPOUND SELECTEDFROM THE GROUP CONSISTING OF THOSE REPRESENTED BY THE FORMULAE: